If you're trying to find an important spot, take a look at my avatar. I recommend the middle finger or middle finger/ring finger combo if you want her to blast fast. Initiate a come hither motion and you'll have to pay 1.75 to wash and 1.75 to dry your sheets. So, make sure she is worth tree fiddy.
I guess all of these tips are applicable to dudes too, but only if they are on their back.